Troubleshoot SMTP Error 550 "Relay Denied"

Learn how to resolve the common e-mail error SMTP 550 "Relay Denied." This error most often happens because of a failure to correctly authenticate with the SMTP server. Learn more about SMTP authentication methods, and how to resolve this error. [...]  

Email Protocols: POP3 vs IMAP

Learn about the difference between POP3 and IMAP e-mail protocols, find out which one will serve your needs best, and learn about the potential consequences of your users choosing one over the other. [...]  

Managing Email on 1&1 Cloud Servers

Learn more about using email with a 1&1 Cloud Server account, including how to set up and use the 1&1 Webmail included with each account, how to configure the DNS and firewall if you prefer to host your own email server, and more. [...]  

Set up Email on a 1&1 Cloud Server With Plesk

For any 1&1 Cloud Server with Plesk, applications like email should always be installed and managed through the Plesk interface. Follow the instructions in this tutorial to learn how to set up email services on a Plesk server. [...]  

Read More